18138717 has 12 divisors (see below), whose sum is σ = 27104220. Its totient is φ = 11675328.

The previous prime is 18138713. The next prime is 18138721. The reversal of 18138717 is 71783181.

It is an interprime number because it is at equal distance from previous prime (18138713) and next prime (18138721).

It can be written as a sum of positive squares in 2 ways, for example, as 6380676 + 11758041 = 2526^2 + 3429^2 .

It is not a de Polignac number, because 18138717 - 2² = 18138713 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18138713) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34488 + ... + 35009.

It is an arithmetic number, because the mean of its divisors is an integer number (2258685).

Almost surely, 2^18138717 is an apocalyptic number.

It is an amenable number.

18138717 is a deficient number, since it is larger than the sum of its proper divisors (8965503).

18138717 is a wasteful number, since it uses less digits than its factorization.

18138717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69532 (or 69529 counting only the distinct ones).

The product of its digits is 9408, while the sum is 36.

The square root of 18138717 is about 4258.9572667497. The cubic root of 18138717 is about 262.7456421702.

The spelling of 18138717 in words is "eighteen million, one hundred thirty-eight thousand, seven hundred seventeen".